Finished swapping an Aspire B3 into a carby Festiva.... No gas, no start???

[Ray]

Alright, here's the senerio.

I bought a B3 from a fuel injected Aspire. After a couple of days of work with a few friends, we got everything running, everything bolted up, etc etc. (We kept the carburator and did NOT swap to efi)

I knew going into this that the mechanical fuel pump on the Festiva engine would not work with the Aspire engine. As we were swapping accessories over, we looked just below the valve cover on the rear, and in the exact same spot as the carby Festiva engine, there was a blank. We removed the blank and the hole looked almost identical to the hole where the fuel pump goes on the Festiva engine. It bolted right up - I was ecstatic.

And yes, I am absolutely sure this is an Aspire engine. The belts along with the cams are the way they are supposed to be for an Aspire.

Anyway! We got everything hooked up, and tried to start it. No dice. We poured a little gas into the carb and the car purred like a kitten. It was quiet, and sounded exactly the way it should.

So my conclusion is this - the mechanical fuel pump bolts in, but the head is different, and does not provide the mechanical power the old fuel pump needs. But I was prepared for this! I bought an electric fuel pump off of ebay the produces 3-5 psi. I fitted it onto the fuel line as close to the fuel tank as I could get.

You can hear the the new electric fuel pump turn on and start pumping, but gas is still not getting to the carb for some reason. Keep in mind that I left the mechanical fuel pump in place, because I did not want to deal with the headache of figuring out how to re-route the fuel lines under the hood to get rid of the mechanical fuel pump. Would keeping the old fuel pump in place keep gas from moving to the carburator properly? If so, does anyone have any idea how to loop around the fuel lines to delete the mechanical fuel pump?

All of this being said, any advice???

[Ray]

Minor detail:

A while back, I ran the car out of gas. This is the first time it has happened in it's 403,900 miles. Every since then, the car has had a little bit of hesitation to it when you put the petal down to the floor. I have never changed the fuel filter, nor do I have any idea where it's at. (havent tried looking for it)

Would this be enough to prevent the new electric fuel pump from pushing gas to the engine? I never had any difficulty starting or anything other than the slight hesitation with the mechanical fuel pump, and I can't imagine the old fuel pump being Hercules compared to the new one.

[nitrofarm]

The mechanical pump has two valves inside. If one of these is in the closed position it will block flow. To test this theory,just get a straight barbed fitting that fits your fuel line. Put this tube in place of the fuel pump & try running it.PS you need to get an enertia switch wired in series for that fuel pump. Dont ever run a E pump without one.

[Bert]

The mechanical pump has two valves inside. If one of these is in the closed position it will block flow. To test this theory,just get a straight barbed fitting that fits your fuel line. Put this tube in place of the fuel pump & try running it.PS you need to get an enertia switch wired in series for that fuel pump. Dont ever run a E pump without one.

Great advice!

However "Don't ever run an electric pump without one (an inertia switch)" does puzzle me. I'm presuming this is practical advice regarding safety and not at all about operating issues. Truth be known drivers in accidents are usually too rattled to think about turning off the ignition, and an electric pump can potentially empty the entire gas tank to create a spectacular inferno.

[georgeb]

I wonder if the Aspire cam doesn't have the lobe to run the fuel pump.

[Bert]

I wonder if the Aspire cam doesn't have the lobe to run the fuel pump.

This is what nitrofarm was alluding to. No cam lobe therefore no turn of a mechanical fuel pump, and therefore a blocked path for fuel via a tagged-on electrical pump on the same fuel line.

[Festy46]

Remove the fuel pump and replace the fuel pump block off plate. In case you didn't understand what Nitrofarm was telling you to do: Get one of the fittings pictured below and a couple hose clamps and you can eliminate the fuel pump by splicing your fuel line together. Remember that there are two fuel lines going to the tank (a suction and a return line). If you connected the fuel pump to the return line, it will not pick up gas out of the tank. In lieu of an inertia switch, you can wire in a normally open pressure switch with a "T" fitting where your current oil pressure sending unit attaches to the block. That way any time you don't have oil pressure (engine stopped), your fuel pump will stop pumping also.

[Nerd Racing]

I wonder if the Aspire cam doesn't have the lobe to run the fuel pump.

BINGO!

[georgeb]

The mech pump has a return circuit. I guess you have to have a T connector between pump and carb to run an inline unit unless the inline unit is puny.

[Ray]

Remove the fuel pump and replace the fuel pump block off plate. In case you didn't understand what Nitrofarm was telling you to do: Get one of the fittings pictured below and a couple hose clamps and you can eliminate the fuel pump by splicing your fuel line together. Remember that there are two fuel lines going to the tank (a suction and a return line). If you connected the fuel pump to the return line, it will not pick up gas out of the tank. In lieu of an inertia switch, you can wire in a normally open pressure switch with a "T" fitting where your current oil pressure sending unit attaches to the block. That way any time you don't have oil pressure (engine stopped), your fuel pump will stop pumping also.

The mech pump has a return circuit. I guess you have to have a T connector between pump and carb to run an inline unit unless the inline unit is puny.

Yeah, I got what he was saying. But like what georgeb said, there are three lines running to the mech fuel pump. I have little to almost no knowledge about gas lines, fuel pumps, etc (every engine swap I've done has been pretty much plug 'n play with fuel lines), so please forgive my ignorance

But the three lines on the pump are gas in, gas out, and return, right? I get the concept behind linking the gas in and gas out lines, but what about the third line? Run it to a point before the fuel pump, splice it, and slap a T fitting on there? o.O

[Ray]

Waaaait, I just thought of something. The inline pump doesn't have a third line, the mech pump did. So in therey, I should just be able to cap that extra return line, right? Seeing as how it can't connect to anything on the new pump

[nitrofarm]

Waaaait, I just thought of something. The inline pump doesn't have a third line, the mech pump did. So in therey, I should just be able to cap that extra return line, right? Seeing as how it can't connect to anything on the new pump

Yes that will work fine,and you might want to get a metering jet and JB weld it into the the "Return" portion of your new "T" fitting. Not mandatory but might prevent a high rpm fuel starvation issue.(Especially if the E pump your using is very low volume.) Cant you go back and get the Aspire inertia switch for free? They are so easy to remove and wire up....

[Ray]

Yes that will work fine,and you might want to get a metering jet and JB weld it into the the "Return" portion of your new "T" fitting. Not mandatory but might prevent a high rpm fuel starvation issue.(Especially if the E pump your using is very low volume.) Cant you go back and get the Aspire inertia switch for free? They are so easy to remove and wire up....

No, but I have a generic one on the way. Better wiring that in than burning alive, I'm sure!

[Bert]

Now I want to hear from you that the sucker actually runs! I'm talking about the car, of course.
I have a lo-mile 97 Aspire engine sitting around waiting for the day I swap it into a Festy (which is an EFI) and there is all kinds of non-compatible stuff bolted on there that has to be dealt with in order to do this. You fellas did well to adapt to a carb car.

[zoe60]

When I had an Aspire engine I just put the cam and rockers from my old engine in it. Pretty easy and it ran great.